Preparation of meta-dioxanes



Patented Apr. 18, 1950 ZUNL'TEE D je'Sis'lTATE-S PA? gElsIT gg F-FllGiE37 .1=;I t1icA1t 'r1o or ErArmoXAn s Raphael Rosenf'Elizabeth, andErving Arund'ale,

Westfield; -"N; J assignors to Standardl-Oil' Developmenti(1ompany, acorporation ofiDelaware NQLDraWing. ApplicationiMay 5,, 1.994 8,

Serial No. 25,308

(o1. :zarmsss) 4 Claims.

"1 This invention; relates; 'toan improved i process for the-production.ofrmetaedioxanes by the reaction of unsaturated compounds of the eneralformula:

where R1 and. R2 is hydrogen or a hydrocarbon radical such as alkyl,aryl, aralkyl, 'alkenyl,--or alkaryl radical which may containsubstituent groupssuch as alkoxy, alkoxy alkyl; or; chloro' --2 theypermit =cornpletecontrol of: the reaction, produce amaximum :of- "thedesirable products, reduce the formation of :wide' boiling by-prodnets,and even then permit a iasterreaction-than can lee-obtained-with adilute mineralacid catalyst of thesame concentration on a weight basis.

-Accordingto the present invention, QIE'fiIlS,

particularly the primary and secondary olefins,

groups with aldehydes; substituted "aldehydes,

reactants at between 100". and 200C. in the presence of asuitablecatalyst. Whenpreparedffrom or compounds readily converted tothe olefins, e. g., alcohols, alkyl halides, etc., or other unsaturatedcompounds, are condensed with aldehydes, thioaldehydes, substitutedaldehydes, formals, acetals, or ketones in the presence of an aqueousboron fluoride catalyst in which the ratio of water to boron fluoride isbetween 6-18 .(preferablylO-ll) mols of water per mol of boron fluoride.The present invention, therefore, can- ,templates catalysts containingup to but never more than 39% boron fluoride on a weight basis. Theboron'fluoride may also be associated with water and-mineral: acids,-e-. g.;1-I 2SO4,HF, HQl. H3PO'4; etc.

'The :reaction temperature, ranges between 10 and'.75Grandthe-particulari-temperature em,-

. ployed dependspn-the olefin ,or unsaturatedlcomiglyliols amghydes" iig gfii pound used-:andth'e boron fluoride watercatalyst fh'gigigi ecauseo e concentration. :Apressure :at-least equivalent to V .the .vapor:-pressure::.,of;the reactionmixture at Mgta'dmxanes.havefils-o'beeriprepared l the temperature of-thereaction should be maindensm-golefinswlthfildehydfos'm'thePresence m tained during the reaction. The reactionprese anac1draot ngcatalyst,having an ac d, concenasurewmjmereforevaryiimmvsubflstantiauy annoy of m the pheric -pressure' topressures-ofseveral---atmosapplication of J. J. Rittenjfienal 'No.,l3.33 pheresy filed May 11, 1940, now Ratent;No. 5,2,36

dmxanes' F --9 W 5 olefin-or other v unsaturated compound Metadioxanesare colorless, mobile-liquids completely are assistant:stressesissued... pri ,,I e 8. e process 0 we presr m; invention is animprovement (War previous 40 mg: agents-for motor fuels,- and asintermediates imethodsjor preparing meta dioxanes.

The two patents mentioned ab0ve;;claim"'the lcondensationhofoolefinswith aldehydes using a .boron; fluoride-water catalyst in which.one mol to be uncontrollable and large'iainounts of wide boilingby-productsare"'obtaineidx nnderthese rendit ons Weh v .nowidisc e t diatibo n [fluoride-water catalysts containing-about 6-18 1 (preferably10-11) mols-iof "water perhmolbf 'bo'ron" fluoride are distinctlyadvantageous in that for further chemical synthe'sis.

"Compounds suitable as starting materials 'in this process "includeprimary 1 and secondary secondary-butyl chloride, etc.)unsaturated-halides (allyl chloride) vinyl chloride, unsaturated ethers,dioleflns, '(bu-tadiene; piperylene) olefin polymers, etc.

Aldehydes suitable for 7 use in thisprocess inelude paraformaldehyde,"Eormalin; trioxane; :oth- -erpolyn ersof' formaldehyde; acetaldehyde;propi onal-dehyde-, benzaldehyde, methoxyacetaldehyde,

or compounds capable of decomposing under the reaction conditions toyield aldehydes, e. g., formals, acetals, hexamethylenetetramine, etc.

The general procedure, according to the present invention, is to chargea pressure vessel with the reactants and catalyst and to agitate thecontents of the reactor for a length of time required for completion ofthe reaction. It is desired to use a pressure vessel equipped with meansof agitation in order to insure adequate contact between the reactantsand the catalyst. After the reaction is complete, the contents oftheves'sel are permitted to cool, excess olefin or gaseous products arebled ofi, and the mixture isthen neutralized with an alkali such assodium carbonate or sodium hydroxide. The neutralized mixture is thensteam distilled. The distillate is treated with sodium chloride or asimilar salt,

the aqueous saline solution is separated from' 4 uct was removed fromthe bomb and neutralized with a solution of sodium hydroxide whereuponit was steam distilled. The distillate which was taken overhead up to109 C. was salted out I with sodium chloride and the upper productlayer.

separated, dried over anhydrous potassium carbonate, and finallyfractionated with cuts bein taken between -102 C. (isopropyl alcohol)and between l02-l2'7 C. (4-methy1 meta dioxaneq).

The residue from the fractionation (above 127- C.) contained higherboiling formals. In addition, the residue from the steam distillationwas extracted with absolute alcohol to remove inorganic salts, theextract was filtered, and the alcohol and residual water removed bydistillation under vacuum. The residue containing still higher boilingformals and butylene glycols was finally weighed and the following datawere obtained:

SUMMARY Propylene-formaldehyde condensatio-ns aque ous boron fluoridecatalyst General conditions:

8 mols Formaldehyde 22.7 mols Water 5.4 mols Propylene [Run for 21 hours66 C.]

1 Some unreacted formaldehyde was present at the end of the run.

The reaction was so exothermic that minutes without the application ofheat,

tion. The vacuum distillation residue is mixed with an anhydroussolvent. such as absolute ethyl alcohol, any inorganic solids areseparated from the solution by filtration, and the solvent is removedfrom the filtrate by vacuum distillation. The residue from the latterdistillation. contains the diol or substituted diol formed as a productor by-product in the condensation reaction. *It may be purified byvacuum or atmospheric fractionation.

The reaction as carried out in a batch process shaking and cooling untilthe proper catalyst concentration had been obtained. ,The contents ofthe flask were then transferred to a2 liter stainless steel bomb, thebomb was closed, and inserted in an isopropyl alcohol-Dry Ice bath. Therequired quantity of propylene was then distilled into the bomb whichwas finally placed on an air-shaker where it was shaken and heated at atemperature of 65-66 C. for 21% hours. The bomb was then cooled and theexcess propylene gas run 011 througha wet test meter. The prodthe bombtemperature increased from 28 0. to 65 C.in seven The data given in thetable indicate thatat higher moi ratios of water/BFa above.l8/1 thereaction is incomplete. However, under the same conditions but atcatalyst ratios below 6/1,-*the reaction is not easily controlled, theyield of desired 4-methyl meta dioxane is low, and theyield of higherformals high. In other words, increas ing the BFs catalyst concentrationresults'ima reduced yield of meta dioxane and an increased yield ofhigher boiling products. Therewould appear to be a maximum dioxane yieldaround an 11/1 mol ratio of water/BFa at the particular operatingtemperature employed.

What is claimed is:

l. The process which comprises condensing an aldehyde with propylene at,a temperature of between 65 .C. and C. under a pressure at least equalto the vapor pressure of the reaction mixture in the presence of anaqueous boron fluoride catalyst in which the ratio of water to boronfluoride is between 10 and 18 mols of Water per mol of boron fluoride,and recovering the products of the reaction. r v

2; The process which comprises condensing formaldehyde with propylene ata temperature of between 65 C. and 75 C. under a pressure at least equalto the vapor pressure of the reaction mixture in the presence of anaqueous boron fluoride catalyst in which the ratio of water to boronfluoride is between 10 and 18 mols of water per mol of boron fluoride,and recovering the products of the reaction. I

formaldehyde with propylene at a temperature 7 or a o 6. en r a Pr en al s ua to the vapor pressure of the reaction mixture in the presence ofan aqueous boron fluoride catalyst in which the ratio of water to boronfluoride is between 10 and 11 mols of water per mol of boron fluoride,and recovering the products of the reaction.

4. The process which comprises condensing formaldehyde with propylene inthe ratio of 1.5 mols of formaldehyde per mol of propylene at (SS-66 C.under a pressure at least equal to the vapor pressure of the reactionmixture in the presence of an aqueous boron fluoride catalyst in whichthe ratio of water to boron fluoride catalyst is between 10 and 11 molsof water per mol of boron fluoride, neutralizing the reaction mass 15RAPHAEL ROSEN. ERVING ARUNDALE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number

4. THE PROCESS WHICH COMPRISES CONDENSING FORMALDEHYDE WITH PROPYLENE INTHE RATIO OF 1.5 MOLS OF FORMALDEHYDE PER MOL OF PROPYLENE AT 65-66*C.UNDER A PRESSURE AT LEAST EQUAL TO THE VAPOR PRESSURE OF THE REACTIONMIXTURE IN THE PRESENCE OF AN AQUEOUS BORON FLUORIDE CATALYST IN WHICHTHE RATIO OF WATER TO BORON FLUORIDE CATALYST IS BETWEEN 10 TO 11 MOLSOF WATER PER MOL OF BORON FLUORIDE, NEUTRALIZING THE REACTION MASS WITHALKALI, STEAM DISTILLING THE NEUTRALIZED MASS, DRYING THE ORGANICPORTION OF THE STEAM DISTILLATE, AND FRACTIONATING THE DRIED MATERIAL INORDER TO ISOLATE 4-METHYL META-DIOXANE.